> But they don't demand the same control over laptops and desktops. Only phones. Why is that?

Oh, but they do. PCs (and Macbooks) are products of an earlier era, and the solutions of control evolved along; it looks chaotic, but that's because it's where the R&D happened over the past decades, which ultimately produced a cleaner - and more easily identifiable - mobile control ecosystem. But it's all there, if you look closely. To name few major groups:

- Many generations of DRM plugins for games, then for streaming media

- Trusted computing hardware

- Intel Management Engine and other firmware backdoors routinely inserted into hardware

- Endpoint security software, deployed widely on corporate-owned machines

Mobile solutions are just version 2.0, built on top of all that R&D.

> Granted I can't deposit a check with my laptop but I can do any other banking I wish to do.

This is the insidious part: for many banks, this is only tolerated because they force you to use their proprietary app on a trusted mobile device as a second factor! At this point, it doesn't really matter how well-controlled your main browsing platform is, because you have to use your phone anyway, and there the control happens. And, "for your convenience", the mobile app isn't just a physical security token, but lets you do banking too, which allows them to gradually deprecate the web experience.